 :root {
            --primary: #3498db;
            --primary-dark: #2980b9;
            --secondary: #e74c3c;
            --accent: #f39c12;
            --light: #ecf0f1;
            --dark: #2c3e50;
            --gray: #95a5a6;
            --success: #27ae60;
            --card-bg: rgba(255, 255, 255, 0.85);
            --glass-bg: rgba(255, 255, 255, 0.15);
            --shadow: 0 8px 32px rgba(31, 38, 135, 0.15);
            --transition: all 0.3s ease;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
            color: var(--dark);
            min-height: 100vh;
            position: relative;
            overflow-x: hidden;
        }

        body::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: url('') repeat;
            opacity: 0.1;
            z-index: -1;
        }

        /* 导航栏样式 */
        header {
            background-color: var(--card-bg);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
            padding: 0.5rem 2rem;
        }

        nav {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo-container {
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .logo {
            height: 60px;
            width: auto;
            object-fit: contain;
        }

        .brand-name {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--dark);
            letter-spacing: -0.5px;
        }

        .brand-name span {
            color: var(--primary);
        }

        .nav-links {
            display: flex;
            gap: 1.5rem;
            align-items: center;
        }

        .nav-links a {
            color: var(--dark);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 10px 15px;
            border-radius: 50px;
        }

        .nav-links a:hover {
            background-color: rgba(52, 152, 219, 0.1);
            color: var(--primary);
        }

        .nav-links a.active {
            background-color: var(--primary);
            color: white;
        }

        .user-info {
            position: relative;
            display: flex;
            align-items: center;
            gap: 10px;
            cursor: pointer;
            padding: 5px 10px;
            border-radius: 50px;
            transition: var(--transition);
        }

        .user-info:hover {
            background-color: rgba(52, 152, 219, 0.1);
        }

        .user-avatar {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            overflow: hidden;
            border: 2px solid var(--primary);
        }

        .user-avatar img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .avatar-dropdown {
            position: absolute;
            top: 100%;
            right: 0;
            background-color: var(--card-bg);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            box-shadow: var(--shadow);
            border-radius: 10px;
            padding: 10px 0;
            width: 180px;
            z-index: 100;
            opacity: 0;
            visibility: hidden;
            transform: translateY(10px);
            transition: var(--transition);
        }

        .user-info:hover .avatar-dropdown {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }

        .dropdown-item {
            display: block;
            padding: 10px 20px;
            color: var(--dark);
            text-decoration: none;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .dropdown-item:hover {
            background-color: rgba(52, 152, 219, 0.1);
            color: var(--primary);
        }

        .hamburger {
            display: none;
            cursor: pointer;
            font-size: 1.5rem;
        }

        /* 活动页面样式 */
        .coupon-activities {
            max-width: 1400px;
            margin: 3rem auto;
            padding: 0 2rem;
        }

        .section-header {
            text-align: center;
            margin-bottom: 3rem;
        }

        .section-title {
            font-size: 2.5rem;
            color: var(--dark);
            margin-bottom: 1rem;
            position: relative;
            display: inline-block;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--primary);
            border-radius: 2px;
        }

        .section-subtitle {
            color: var(--gray);
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto;
        }

        .coupon-filters {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 15px;
            margin-bottom: 2rem;
        }

        .filter-btn {
            padding: 12px 25px;
            background: var(--glass-bg);
            backdrop-filter: blur(5px);
            border: 1px solid rgba(255, 255, 255, 0.5);
            border-radius: 50px;
            font-weight: 500;
            cursor: pointer;
            transition: var(--transition);
            color: var(--dark);
        }

        .filter-btn:hover {
            background: rgba(52, 152, 219, 0.2);
            border-color: var(--primary);
        }

        .filter-btn.active {
            background: var(--primary);
            color: white;
            border-color: var(--primary);
        }

        .coupon-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
            gap: 30px;
            margin-top: 2rem;
        }

        .coupon-card {
            background: var(--card-bg);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            position: relative;
            display: flex;
            flex-direction: column;
            min-height: 200px;
        }

        .coupon-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 15px 40px rgba(31, 38, 135, 0.2);
        }

        .coupon-header {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            color: white;
            padding: 20px;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .coupon-value {
            font-size: 2.5rem;
            font-weight: 700;
            display: flex;
            align-items: flex-start;
        }

        .coupon-value span {
            font-size: 1.5rem;
            margin-top: 5px;
        }

        .coupon-type {
            background: rgba(255, 255, 255, 0.2);
            padding: 5px 15px;
            border-radius: 20px;
            font-size: 0.9rem;
        }

        .coupon-body {
            padding: 20px;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }

        .coupon-title {
            font-size: 1.4rem;
            margin-bottom: 10px;
            color: var(--dark);
        }

        .coupon-condition {
            color: var(--gray);
            margin-bottom: 8px;
            font-size: 0.95rem;
            line-height: 1.5;
        }
        
        /* 新增领取条件样式 */
        .coupon-requirement {
            color: var(--accent);
            margin-bottom: 8px;
            font-size: 0.9rem;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .coupon-requirement i {
            font-size: 0.8rem;
        }

        .coupon-expiry {
            color: var(--gray);
            font-size: 0.85rem;
            margin-top: auto;
            padding-top: 10px;
            border-top: 1px dashed #eee;
        }

        .coupon-actions {
            padding: 15px 20px;
            display: flex;
            justify-content: center;
        }

        .claim-btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 10px 25px;
            border-radius: 50px;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
            width: 100%;
            justify-content: center;
        }

        .claim-btn:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
        }

        .claim-btn:disabled {
            background: var(--gray);
            cursor: not-allowed;
            transform: none;
        }

        .coupon-tag {
            position: absolute;
            top: 15px;
            right: -30px;
            background: var(--secondary);
            color: white;
            padding: 5px 30px;
            transform: rotate(45deg);
            font-size: 0.8rem;
            font-weight: 600;
            z-index: 2;
        }

        .new-user-badge {
            position: absolute;
            top: 10px;
            left: -10px;
            background: var(--accent);
            color: white;
            padding: 5px 15px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            z-index: 2;
            box-shadow: 0 3px 10px rgba(0,0,0,0.1);
        }

        .empty-state {
            grid-column: 1 / -1;
            text-align: center;
            padding: 3rem;
            background: var(--card-bg);
            border-radius: 15px;
            box-shadow: var(--shadow);
        }

        .empty-state i {
            font-size: 3rem;
            color: var(--gray);
            margin-bottom: 1rem;
        }

        .empty-state p {
            color: var(--gray);
            font-size: 1.2rem;
        }

        /* 动画效果 */
        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.05); }
            100% { transform: scale(1); }
        }

        .pulse {
            animation: pulse 2s infinite;
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            .coupon-grid {
                grid-template-columns: 1fr;
            }
            
            .nav-links {
                position: fixed;
                top: 80px;
                left: 0;
                background: var(--card-bg);
                backdrop-filter: blur(10px);
                width: 100%;
                flex-direction: column;
                align-items: center;
                padding: 2rem 0;
                gap: 1.5rem;
                box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
                clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
                transition: var(--transition);
            }

            .nav-links.active {
                clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
            }

            .hamburger {
                display: block;
            }

            .section-title {
                font-size: 2rem;
            }

            .section-subtitle {
                font-size: 1rem;
            }
        }